NGC 2346

NGC 2346
星雲
	哈伯太空望遠鏡拍攝的NGC 2346
觀測資料: J2000.0 epoch
赤經	07h 09m 22.52166s
赤緯	−00° 48′ 23.6112″
距離	4,760 ly（1,458 pc）光年
視星等 (V)	9.6
視尺度(V)	0.91′
星座	麒麟座
物理性質
半徑	2 ly
名稱	蝴蝶星雲、蟲子星雲
	相關條目：星雲列表

NGC 2346是位於麒麟座中，靠近天球赤道的一個行星狀星雲^[5]，在麒麟座δ的東南東方距離不到1度之處^[6]。它被非正式地稱為蝴蝶星雲^[3]。星雲明亮而顯眼，視星等為9.6^[3]，並已被廣泛研究。它最顯著的特徵之一是其異常低溫的中心恆星，這是一對光譜聯星，以及它不尋常的形狀。

這個星雲呈現雙極性，氣體流出速度適中，在8〜11km/s的範圍內，而中心則由膨脹的分子氣體環包圍。星雲的電子密度約為每立方釐米400。星雲的電離是來自聯星伴星的紫外線發射的結果^[7]。更強的紅外輻射來自以7004160000000000000♠16 km/s膨脹的分子帶輻射。星雲中分子氣體的質量估計在0.34〜7030367881750000000♠1.85 M_☉的範圍內，並且遠大於電離氣體的質量^[8]。

中心恆星是由一顆A型次巨星和O型次矮星恆星組成的聯星^[9]。該系統的軌道週期為7001160000000000000♠16.00±0.03天^[2]，也是變光週期^[10]，可能是由於它周圍的軌道上有塵埃。塵埃本身被中心恆星加熱，因此NGC 2346在光譜的紅外部分異常明亮。當兩顆恆星中的一顆演化成紅巨星時，它吞沒了它的伴星，並從自身的大氣層中剝離了一圈物質。當紅巨星的核心暴露時，一股快速的恆星風從環的兩側膨脹成兩個"氣泡"。.

圖集

參考資料

^ ^1.0 ^1.1 ^1.2 Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne, J. H. J.; et al. Gaia Data Release 2. Summary of the contents and survey properties. Astronomy & Astrophysics. 2018. Bibcode:2018A&A...616A...1G. arXiv:1804.09365 . doi:10.1051/0004-6361/201833051. VizieR中此天體在蓋亞望遠鏡第二批數據發布的記錄
^ ^2.0 ^2.1 Brown, Alex J.; Jones, David; Boffin, Henri M. J.; Van Winckel, Hans. On the post-common-envelope central star of the planetary nebula NGC 2346. Monthly Notices of the Royal Astronomical Society. February 2019, 482 (4): 4951–4955. Bibcode:2019MNRAS.482.4951B. arXiv:1810.09764 . doi:10.1093/mnras/sty2986.
^ ^3.0 ^3.1 ^3.2 ^3.3 Jenkins, D. A. First Light and Beyond: Making a Success of Astronomical Observing. Springer International Publishing. July 28, 2015: 216. ISBN 9783319188515.
^ Stanghellini, Letizia; et al. The Magellanic Cloud Calibration of the Galactic Planetary Nebula Distance Scale. The Astrophysical Journal. December 10, 2008, 689 (1): 194–202. Bibcode:2008ApJ...689..194S. arXiv:0807.1129 . doi:10.1086/592395.
^ NGC 2346: A Butterfly-Shaped Planetary Nebula. Astronomy Picture of the Day. October 28, 2001 [2020-08-28]. （原始內容存檔於2010-06-29）.
^ Sinnott, Roger W.; Perryman, Michael A. C. Millennium Star Atlas 1. Sky Publishing Corporation and the European Space Agency. 1997: 249. ISBN 0-933346-84-0.
^ Phillips, J. P.; Cuesta, L. Extinction Mapping of the Bipolar Outflow NGC 2346. The Astronomical Journal. January 2000, 119 (1): 335–341. Bibcode:2000AJ....119..335P. doi:10.1086/301170 .
^ Arias, L.; et al. Kinematics of the Molecular Hydrogen from the Planetary Nebula NGC 2346. The Astronomical Journal. December 2001, 122 (6): 3293–3304. Bibcode:2001AJ....122.3293A. doi:10.1086/324446 .
^ González-Santamaría, I.; Manteiga, M.; Manchado, A.; Ulla, A.; Dafonte, C.; López Varela, P. Planetary nebulae in Gaia EDR3: Central star identification, properties, and binarity. Astronomy & Astrophysics. 2021, 656: A51. Bibcode:2021A&A...656A..51G. S2CID 237940344. arXiv:2109.12114 . doi:10.1051/0004-6361/202141916.
^ Samus', N. N; Kazarovets, E. V; Durlevich, O. V; Kireeva, N. N; Pastukhova, E. N. General catalogue of variable stars. Astronomy Reports. 5.1. 2017, 61 (1): 80. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085.

外部連結

維基共享資源上的相關多媒體資源：NGC 2346
每日一天文圖（成大物理分站）: NGC 2346

[GaiaDR2-1] 1.0 ^1.1 ^1.2 Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne, J. H. J.; et al. Gaia Data Release 2. Summary of the contents and survey properties. Astronomy & Astrophysics. 2018. Bibcode:2018A&A...616A...1G. arXiv:1804.09365 . doi:10.1051/0004-6361/201833051. VizieR中此天體在蓋亞望遠鏡第二批數據發布的記錄

[Brown2019-2] 2.0 ^2.1 Brown, Alex J.; Jones, David; Boffin, Henri M. J.; Van Winckel, Hans. On the post-common-envelope central star of the planetary nebula NGC 2346. Monthly Notices of the Royal Astronomical Society. February 2019, 482 (4): 4951–4955. Bibcode:2019MNRAS.482.4951B. arXiv:1810.09764 . doi:10.1093/mnras/sty2986.

[Jenkins2015-3] 3.0 ^3.1 ^3.2 ^3.3 Jenkins, D. A. First Light and Beyond: Making a Success of Astronomical Observing. Springer International Publishing. July 28, 2015: 216. ISBN 9783319188515.

[Stanghellini2008-4] Stanghellini, Letizia; et al. The Magellanic Cloud Calibration of the Galactic Planetary Nebula Distance Scale. The Astrophysical Journal. December 10, 2008, 689 (1): 194–202. Bibcode:2008ApJ...689..194S. arXiv:0807.1129 . doi:10.1086/592395.

[APOD2001-5] NGC 2346: A Butterfly-Shaped Planetary Nebula. Astronomy Picture of the Day. October 28, 2001 [2020-08-28]. （原始內容存檔於2010-06-29）.

[Sinnott1997-6] Sinnott, Roger W.; Perryman, Michael A. C. Millennium Star Atlas 1. Sky Publishing Corporation and the European Space Agency. 1997: 249. ISBN 0-933346-84-0.

[Phillips2000-7] Phillips, J. P.; Cuesta, L. Extinction Mapping of the Bipolar Outflow NGC 2346. The Astronomical Journal. January 2000, 119 (1): 335–341. Bibcode:2000AJ....119..335P. doi:10.1086/301170 .

[Arias2001-8] Arias, L.; et al. Kinematics of the Molecular Hydrogen from the Planetary Nebula NGC 2346. The Astronomical Journal. December 2001, 122 (6): 3293–3304. Bibcode:2001AJ....122.3293A. doi:10.1086/324446 .

[9] González-Santamaría, I.; Manteiga, M.; Manchado, A.; Ulla, A.; Dafonte, C.; López Varela, P. Planetary nebulae in Gaia EDR3: Central star identification, properties, and binarity. Astronomy & Astrophysics. 2021, 656: A51. Bibcode:2021A&A...656A..51G. S2CID 237940344. arXiv:2109.12114 . doi:10.1051/0004-6361/202141916.

[gcvs-10] Samus', N. N; Kazarovets, E. V; Durlevich, O. V; Kireeva, N. N; Pastukhova, E. N. General catalogue of variable stars. Astronomy Reports. 5.1. 2017, 61 (1): 80. Bibcode:2017ARep...61...80S. doi:10.1134/S1063772917010085.

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